Abstract:
:A finite element thermal model of the head has been developed to calculate temperature rises generated in the brain by radiation from cellular telephones and similar electromagnetic devices. A 1 mm resolution MRI dataset was segmented semiautomatically, assigning each volume element to one of ten tissue types. A finite element mesh was then generated using a fully automatic tetrahedral mesh generator developed at NRPB. There are two sources of heat in the model: firstly the natural metabolic heat production; and secondly the power absorbed from the electromagnetic field. The SAR was derived from a finite difference time domain model of the head, coupled to a model 'mobile phone', namely a quarter-wavelength antenna mounted on a metal box. The steady-state temperature distribution was calculated using the standard Pennes 'bioheat equation'. In the normal cerebral cortex the high blood perfusion rate serves to provide an efficient cooling mechanism. In the case of equipment generally available to the public, the maximum temperature rise found in the brain was about 0.1 degrees C. These results will help in the further development of criteria for exposure guidelines, and the technique developed may be used to assess temperature rises associated with SARs for different types of RF exposure.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Wainwright Pdoi
10.1088/0031-9155/45/8/321subject
Has Abstractpub_date
2000-08-01 00:00:00pages
2363-72issue
8eissn
0031-9155issn
1361-6560journal_volume
45pub_type
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